Low row steam generator inspection probe

ABSTRACT

An inspection assembly for insertion inspection of an elongate hollow member. The inspection assembly includes a probe head including at least one sensor for sensing a characteristic of the elongate hollow member as the probe head is moved internally within the elongate hollow member. The assembly includes a flexible shaft connected to the probe head and transmitting a motive force to the probe head to move the probe head within the elongate hollow member. The flexible shaft encloses at least one wire operatively connected between the probe head and at least one component external to the elongate hollow member for sensory operation of the at least one sensor. The flexible shaft is at least partially corrugated.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a continuation of U.S. Provisional PatentApplication No. 61/363,554, filed Jul. 12, 2010, and is a continuationin part of U.S. patent application Ser. No. 13/031,905, filed Feb. 22,2011, both of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention relates to internal inspection probes forinspecting hollow members, such as a hollow member present withinnuclear steam generator.

2. Discussion of Prior Art

Use of inspection/detection devices, such as eddy current sensors, isknown. Such devices can be used, for example, for nuclear generatorhollow tubular members with tortuous bends (e.g., u-bends). However, itis possible know devices to become lodged, or otherwise not able toproceed along the hollow member such that further inspection is notpossible. Thus there is a need for improvements to avoid such issues.

BRIEF DESCRIPTION OF THE INVENTION

The following summary presents a simplified summary in order to providea basic understanding of some aspects of the systems and/or methodsdiscussed herein. This summary is not an extensive overview of thesystems and/or methods discussed herein. It is not intended to identifykey/critical elements or to delineate the scope of such systems and/ormethods. Its sole purpose is to present some concepts in a simplifiedform as a prelude to the more detailed description that is presentedlater.

In accordance with an aspect, the present invention provides aninspection assembly for insertion inspection of an elongate hollowmember. The inspection assembly includes a probe head including at leastone sensor for sensing a characteristic of the elongate hollow member asthe probe head is moved internally within the elongate hollow member.The assembly includes a flexible shaft connected to the probe head andtransmitting a motive force to the probe head to move the probe headwithin the elongate hollow member. The flexible shaft encloses at leastone wire operatively connected between the probe head and at least onecomponent external to the elongate hollow member for sensory operationof the at least one sensor. The flexible shaft is at least partiallycorrugated.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other aspects of the invention will become apparent tothose skilled in the art to which the invention relates upon reading thefollowing description with reference to the accompanying drawings, inwhich:

FIG. 1 is a schematized illustration of an example inspection assemblyin accordance with at least one an aspect of the present invention;

FIG. 2 is an illustration of an example of a nuclear steam generatorhaving a plurality of hollow Members that have at least one bend andwithin which the present invention may be utilized;

FIG. 3 is an illustration of torn-away portions of an example probeshaft of the assembly of FIG. 1 that are within example torn-openportions of a hollow member of the generator of FIG. 2 and in accordancewith at least one aspect of the present invention;

FIG. 4 is view similar to FIG. 3, but shows a torn away portion of aprobe shaft of another example inspection assembly in accordance with anaspect of the present invention; and

FIG. 5 is an illustration of a torn-away portion of an example probeshaft of another example inspection assembly in accordance with anaspect of the present invention in accordance with an aspect of thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

Illustrative embodiments that incorporate one or more aspects of theinvention are described and illustrated in the drawings. Theseillustrated examples are not intended to be overall limitations on theinvention. For example, one or more aspects of the invention can beutilized in other embodiments and even other types of devices. Moreover,certain terminology is used herein for convenience only and is not to betaken as a limitation on the invention. Still further, in the drawings,the same reference numerals are employed for designating the sameelements.

An example of an inspection assembly 10 in accordance with aspects ofthe present invention is schematically shown in FIG. 1. It is to beappreciated that the example is for illustrative purposes only and neednot present specific limitations upon the scope of the presentinvention. The inspection assembly 10 is for insertion inspection of anelongate hollow tubular member 12 (see for example, a tubular membershown within FIG. 2).

The device shown in FIG. 2 is an example generator 14 within which theinspection assembly 10 of FIG. 1 may be utilized. The tubular member 12may be part of a “Low Row” (2.0″ radius tube and greater) U-bend tube ofthe generator 14. The example generator 14 shown within FIG. 2 merelypresents one example environment for the inspection assembly 10. It isto be appreciated that the present invention can be used in otherenvironments (e.g., other tubular environments associated with differentgenerators and other tubular environments that are not part of agenerator). The generator 14 and numerous tubular members 12 (only oneexample tubular member 12 is identified with a reference number,however, any of the shown tubular members could be so identified).

Focusing upon the tubular member 12, the tubular member is hollow andhas a generally arcuate/rounded (e.g., circular or oval cross-section)interior surface 18 (see the example section of FIG. 3). The interiorsurface 18 of the tubular member 12 bounds an interior space 20 of thetubular member 12. In some specific examples the tubular member 12 isrelatively long and has at least one bend 22 (the example bend shown inFIG. 2 is a transition between vertical and horizontal sections of thetubular member). In further specific examples, the tubular member 12 hasmultiple bends (e.g., 22′ shown within FIG. 2) and thus provides atortuous path along its interior space 20. In at least one example, twobends 22, 22′ within the tubular member 12 provides the member with aU-bend configuration. The tubular member 12 can have a varied length.The at least one bend 22 and/or the length of the tubular member 12 canprovide for a path within the tubular member that can be considered tobe tortuous.

Focusing again upon the inspection assembly 10 (FIG. 1), the assembly isfor inspection of the tubular member 12 (FIGS. 2 and 3) from theperspective of the interior space 20 of the tubular member 12. Suchinspection may be in the form of sensing/testing/monitoring at least onecondition of the tubular member 12 from the interior space 20 of thetubular member along the tubular member. The at least one condition neednot be a specific limitation upon the present invention. The inspectionassembly 10 (FIG. 1) includes a probe head 28 and a flexible probe shaft30, with the probe head 28 connected to the probe shaft 30.

At least one sensor 36 (shown generically in FIG. 1) thatsenses/tests/monitors the at least one characteristic (e.g., acondition) of the tubular member 12 is located within/at the probe head28. The type/specifics of the sensor(s) 36 within the probe head 28, andthe probe head 28 itself, need not be specific limitations upon thepresent invention. An example of characteristic (e.g., a condition) tobe sensed/tested/monitored includes structural integrity (e.g., weakenedportions) of the tubular member 12. In one example, the sensor(s) 36include an eddy current sensor that includes wire windings within abobbin and an adjacent magnet. It is to be appreciated that the probehead 28 may include a variety of structures, components, features, andthe like that need not be part of the present invention. The othercomponents may or may not be spaced apart upon a flexible segment. Assuch, the probe head 28 shown within FIG. 1 is merely an example.

The probe head 28 is operatively connected to a sensory operationportion 40 (schematically represented as simply a box) of the inspectionassembly 10 via at least one wire 42. To be cleat; the wire(s) 42 may bea plurality of wires or provided as a wiring bundle and referred to as asimply a wire. Different wires within the plurality or bundle couldaccomplish different functions. The wires) 42 extends to be operativelyconnected to the probe head 28, extends along the length of the probeshaft 30, and extends to be operatively connected to the sensoryoperation portion 40. The wire(s) 42 are housed within an interior ofthe probe shaft 30 as described further following. Electrical powerand/or electrical signals (e.g., control and/or sensory) are passedalong the wire(s) 42 between the probe head 28 and the sensory operationportion 40.

In general, the probe head 28 of the inspection assembly 10 is movedalong the interior space 20 of the tubular member 12 while the probehead 28 senses/tests/monitors. The sensory operation portion 40, via thewire connection to the probe head 28, provides power and/or control andreceives sensory signals from the probe head 28 to make determination(s)about the sensed/tested/monitored at least one condition of the tubularmember 12 as the probe head 28 is moved relatively along the tubularmember. In is to be appreciated that the sensory operation portion 40may contain any suitable structures to perform the functions, such aspower source components, processing components (e.g., one or moremicroprocessors), data storage components, and communication components.The sensory operation portion 40 may be operatively connected to one ormore external or intermediary components (not shown) for control of thesensory operation portion 40 and/or provision of the sensory informationoutside of the shown system and/or other operations.

As mentioned, the probe head 28, with its sensor(s) 36, is moved alongthe tubular member 12. The movement along the tubular member 12 is firstinbound (e.g., inserting) relative to the tubular member 12 and issecondly outbound (e.g., extracting) relative to the tubular shaft. Themotive force to move the probe head 28 along tubular member 12 isimparted via force applied to the probe shaft 30. In one example, themotive force is in the form of manual force applied to the probe Shaft30.

As mentioned, the probe shaft 30 houses the wire(s) 42 extending betweenthe probe head 28 and the sensory operation portion 40. It is possibleto consider the wire(s) 42 to be part of the probe shaft 30. Also,within the shown example, an optional non-metal cable 44 is provided aspart of the probe shaft 30, and the cable is coupled to the probe head28. The cable 44 is housed within the interior of the probe shaft 30 andcan be considered to be part of the probe shaft. The cable 44 providesfor the transmission of tensile force for extracting (i.e., pulling toretrieve) the probe head 28 from the tubular member 12. The cable 44 maybe braided filament cordage. The use of non-metal material for the cable44 helps to avoid imposing electrical interference to the wire(s) 42. Ofcourse, a different construction/material may be used for the cable 44.

Focusing upon the probe shaft 30, the shaft includes a surrounding,hollow sheath tubing 50 that houses and encloses the wire(s) 42 and theoptional cable 44 within an interior space 52 of the sheath tubing 50.The sheath tubing may be made of a polymer material. Within the shownexample, the tubing 50 is a one-piece, continuous and monolithic member.Also within the shown example, the one-piece, continuous and monolithictubing 50 extends along the entire length of the shaft 30. In otherwords, the tubing 50 is not composed of coupled parts within thisexample. However, as shown within another example, it is possible toconstruct a composite shaft via the use of coupled, multiple parts.

The interior space 52 of the sheath tubing 50 is bounded by an interiorsurface (or surface segments) 54 of the sheath tubing 50. Thecross-sectional area of the interior space 52 may be any suitablecross-section dimension for acceptance of the wire(s) 42 and optionalcable 44 therein. It is possible that the cross-sectional size of theinterior space 52 may vary along its length. It is to be noted that FIG.3 shows the wire(s) 42 and the cable 44 filling only part of the volumeof the sheath tubing. Such is only an example and permits ease ofviewing the different components, and should not be taken as a requiredlimitation upon the present invention. It is certainly possible that thewire(s) 42 and the cable 44 fill the volume of the sheath tubing, andsuch is presented within a following discussion.

The overall length of the probe shaft 30, and specifically the sheathtubing 50, may be any suitable length. However, within one example thelength is sufficiently long to meet or exceed a length measured alongthe entire elongate extent of the tubular member 12. For such anexample, the probe head 28 may be moved along the entire elongate extentof the tubular member via insertion movement of the probe shaft 30 intothe tubular member 12. Recall that it is force applied to the sheathtubing 50 of the probe shaft 30 that moves the probe head 28 along theinsertion direction of the tubular member. With regard to length of thewire(s) 42, the length is of course at least a great as the sheathtubing 50, but also sufficiently long to be operatively connected to thesensory operation portion 40. With regard to length of the cable 44, thelength is of course at least as great as the sheath tubing 50, but alsosufficiently long to be engaged (e.g., grasped) for application oftensile (i.e., pulling) force for extracting to retrieve the probe shaft30 and probe head 28.

The probe shaft 30, with the included wire(s) 42 and cable 44, isflexible. The flexibility allows the probe shaft 30 to proceed alongbends (e.g., 22, 22′) of the tubular member 12. Yet the probe shaft 30has sufficient rigidity to allow insertion into the tubular member 12and move the probe head 28 along the extent of the tubular member 12.

In accordance with one aspect, probe shaft 30 includes at least onefeature or means for improving ease of moving the probe shaft 30 and theprobe head 28 of the inspection assembly 10 along the tubular member 12.Such at least one feature or means may include reducing friction thatotherwise may occur between the probe shaft 30 and the tubular member 12and/or negotiating the torturous path of the tubular member 12.

Within one specific example, the probe shaft 30 has corrugations 60, asa structural feature or means, on its exterior. It is to be appreciatedthat the corrugations 60 on the probe shaft 30 may provide for improvingthe ease of movement and are thus an example means for improving theease of movement. Within the shown example, the corrugations 60 arepresent along the entire extent of the probe shaft 30. However, it is tobe appreciated that the corrugations 60 may only be present along aportion of the entire extent of the probe shaft 30. Also within theshown example, the corrugations 60 are at generally evenly spacedintervals along the probe shaft 30. However, the corrugations 60 may beat varied intervals (e.g., a greater number of corrugations 60 or ashorter spacing interval between adjacent corrugations near the probehead 28). The corrugations 60 can be any series of localizeddeformations, crimpings, undulations, flexing/elongation points, or thelike. In one example, the corrugation can be implemented by crimping toplastically deform the sheath tubing 50 at a series of locations alongits length. In another example, the corrugations are formed via molding,forming or the like.

One example of the corrugations 60 on probe shaft 30 is shown in FIG. 3.Within the shown example, the corrugations 60 are on the sheath tubing50. In other words, the sheath tubing 50 of probe shaft 30 is corrugated(i.e., has the corrugations 60). Associated with the examplecorrugations 60, the exterior of the sheath tubing 50 of the probe shaft30 has segments 50A and 50B that have alternating diameter thicknesses.Within the shown example of FIG. 3, the diameter D1 at the segments 50Ais smaller than the diameter D2 at the segments 50B. Thus, the shaftsegments 50A and 50B alternate to have respectively smaller andrespectively larger diameters. It should be noted that the values of D1and D2 are both smaller that the value of the diameter D3, which is theinterior diameter D3 of the tubular member 12. It should be furthernoted that the values, relationships, etc. of the dimension D1, D2 andD3 shown within FIG. 3 are only examples and may differ and may beexaggerated for illustrative purposes.

The different diameters D1 and D2 of the alternating segments 50A and50B may be attendant with the creation of the corrugations. Moreover, itis possible to consider the alternation of the diameters to beconsidered to be the corrugation. Also, it should be appreciated thatthere may be some variation of the diameter D1 or D2 at the segments 50Aand 50B, respectively, along the extent of the sheath tubing 50 of theprobe shaft 30. It should be appreciated that the alternation ofsegments 50A and 50B, is to provide alternation of relatively smallerand relatively greater diameter segments. Still further, although thealternation is between segments with two different diameters, it ispossible to have segments of a different number of diameters.

It is contemplated that the corrugations 60 lower the contact areabetween the probe shaft 30 and the tubular member 12, which reducesfriction. It is also contemplated that the corrugations 60 also appearsto help make the probe shaft 30 more flexible, thus helping it traversea bend 22 more easily. Turning to the specific example shown in FIG. 3,it contemplated that the segments 50A and 50B provided a function ofreducing an overall amount of contact between the probe shaft 30 and theinterior surface 18 of the tubular member 12. For example, therelatively larger diameter segments 50B may help to reduce (e.g., avoid)the contact between the relatively smaller diameter segments 50A and theinterior surface 18 of the tubular member 12. Such reduced contactshould provide for reduced friction between the probe shaft 30 and thetubular member 12.

It is also contemplated that the presence of the corrugations 60 mayhave other benefits. For example, the corrugations 60 may provide for abetter ability to grasp and transmit force to the probe shaft 30. Suchability may be useful during insertion/extraction of the probe shaft 30relative to the tubular member 12. Also, if a mechanized device is usedfor insertion/extraction of the probe shaft 30 relative to the tubularmember 12, the corrugations 60 may provide for better traction by itemssuch as pushing wheels or pushing tracks. Such better traction may helpreduce slippage and increases probe shaft life.

It is contemplated that changes and/or modifications can be accomplishedwithout leaving the scope of the present invention. An example ispresented within FIG. 4, which is a segment of a flexible probe shaft30′ within a segment of am elongate tubular member 12′. For ease andefficiency of understanding, structures that are generally similar topreviously described structures are identified via similar numbers, butwith the numbers including “′” (prime). The example of FIG. 4 shows amodification in which the probe shaft 30′ does not include a hollowsheath tubing. Instead, the probe shaft 30′ may be provided as a sheathencasement 50′ with which at least one wire 42′ is built-in andenclosed. Such can be considered to provide a single shaft. In general,the probe shaft 30 does not include an interior space and the shaft 30′can be considered solid. The shown example includes an optional cable44′. Nonetheless, the probe shaft has series of alternating segments50A′ and 50B′, which have relatively smaller and relatively greaterdiameters D1′ and D2′, respectively.

Another example modification is presented within FIG. 5, which shows asegment of a probe shaft 30″. For ease and efficiency of understanding,structures that are generally similar to previously described structuresare identified via similar numbers, but with the numbers including “″”(double prime). Within this example, the probe shaft 30″ is a compositeshaft, with multiple parts. The example has two parts 76, 78 that arejoined together with a coupling 82. However, it is to be appreciatedthat it is possible to prepare/define/provide the two parts 76, 78 via adifferent approach (e.g., process and/or provide treatment to one partdifferent than the other part).

The coupling 82 is secured to the two segments via any suitableconnection means 84, such as adhesive, friction engagement, crimpingmembers or the like. It is to be appreciated that the coupling 82 isonly schematically shown and thus may have a variety ofconstructions/configurations. Within the shown example, the coupling 82has a hollow bore to permit passage of the wire(s) 42″ and an optionalcable 44″.

It is to be appreciated that the lengths of the first and second parts76, 78 can be varied. It is possible that the two parts 76, 78 (firstand second parts) that have at least one dissimilarity. Examples of suchdissimilarity may include diameter thickness, materials, etc. Suchdissimilarity may provide for improving ease of moving.

Even though the probe shaft 30′ has two parts 76 and 78, the two partseach have some corrugations 60″. The corrugations 60″ may be presentupon all or part of the respective extents of the two parts 76 and 78.The first part 76 has alternating segments 50A″ and 50B″ that haverelatively smaller and relatively greater diameters D1′ and D2′,respectively. Similarly, the second part 78 has alternating segments 50Cand 50D have relatively smaller and relatively greater diameters D3 andD4, respectively. It should be appreciated that the identified diametersD1″ and D2″ of the first part 76 may or may not have a relationship tothe identified diameters D3 and D4 of the second part 78.

In recap, the present invention provides aspects such as an inspectionassembly for insertion inspection of an elongate hollow member. Theinspection assembly includes a probe head including at least one sensorfor sensing a characteristic of the elongate hollow member as the probehead is moved internally within the elongate hollow member. The assemblyincludes a flexible shaft connected to the probe head and transmitting amotive force to the probe head to move the probe head within theelongate hollow member. The flexible shaft encloses at least one wireoperatively connected between the probe head and at least one componentexternal to the elongate hollow member for sensory operation of the atleast one sensor. The flexible shaft is at least partially corrugated.

Some additional aspects include that the flexible shaft can have alength extending between the probe head and a location external to theelongate hollow member and that the flexible shaft can have corrugationsspaced along the entire length. The flexible shaft can include an outertubing that extends along the entire length of the flexible shaft and isa one-piece, continuous and monolithic member. The corrugations on theflexible shaft can bound shaft segments that have differing diameters.The shaft segments can alternate to have respectively smaller andrespectively larger diameters. The flexible shaft can be made of apolymer material.

The various aspects presented herein can provide for improving anability to follow a torturous path of the elongate tubular member 12 andfor aiding in kink prevention of the flexible shaft 30.

The invention has been described with reference to the exampleembodiments described above. Modifications and alterations will occur toothers upon a reading and understanding of this specification. Exampleembodiments incorporating one or more aspects of the invention areintended to include all such modifications and alterations insofar asthey come within the scope of the appended claims.

1. An inspection assembly for insertion inspection of an elongate hollowmember, the inspection assembly including: a probe head including atleast one sensor for sensing a characteristic of the elongate hollowmember as the probe head is moved internally within the elongate hollowmember; and a flexible shaft connected to the probe head andtransmitting a motive force to the probe head to move the probe headwithin the elongate hollow member, the flexible shaft enclosing at leastone wire operatively connected between the probe head and at least onecomponent external to the elongate hollow member for sensory operationof the at least one sensor, and the flexible shaft being at leastpartially corrugated.
 2. An inspection assembly as set forth in claim 1,wherein the flexible shaft having a length extending between the probehead and a location external to the elongate hollow member, the flexibleshaft having corrugations spaced along the entire length.
 3. Aninspection assembly as set forth in claim 1, wherein the flexible shaftincludes an outer tubing that extends along the entire length of theflexible shaft and is a one-piece, continuous and monolithic member. 4.An inspection assembly as set forth in claim 1, wherein corrugations onthe flexible shaft bound shaft segments that have differing diameters.5. An inspection assembly as set forth in claim 4, wherein the shaftsegments alternate to have respectively smaller and respectively largerdiameters.
 6. An inspection assembly as set forth in claim 1, whereinthe flexible shaft is made of a polymer material.